So, I found this other aquarium controller code at http://code.google.com/p/stilo/ that had ported a javascript implementation of a Moonrise/set calculator into Arduino. I have adapted it to the RA libraries and it looks like it's working great.

Anyway if you want to have your moonlights follow an actual rise/set calculated based on GPS location, then here's what you have to do..

Yeah, I'm using the same lat / long right now that I'm using for my SunLocation, but they are not tied to each other. So I'm just setting the same variables. I wanted to keep these seperate so they can stand alone...